Engineering topics
Townes, S.
Publications and source records attributed to Townes, S..
The Optical Communications Telescope Laboratory (OCTL)
No abstract available
Mars Mission Scenario: Data Volume and PDT Notes
Objectives of this work are: (1) Investigate methods for quantifying the value of interoperability for deep space missions: A network of optical receive stations Each one potentially owned by a different space agency. Reduces overall cost to any individual agency Provides geographically diverse locations to mitigate weather problems (clouds, wind, rain, dust, etc.) (2) Metrics: a. Total data volume returned over mission duration b. Percent data transferred (PDT) or something similar.
Deep-Space Optical Terminals
We eport on engineering trades that led to the conceptual design of a laser communications terminal for spacecraft probing Mars. The flight terminal, the ground receiver and the ground transmitter subsystems are described. The flight terminal point design has 0.25 Gb/s downlink data-rate capability from the Mars close distance (0.42 AU). Capability for uplink data-rate of 0.3 Mb/s and ranging with 30 cm precision are also addressed.
Deep-Space Optical Terminals (DOT)
A conceptual design study titled Deep-Space Optical Terminals was recently completed for an optical communication technology demonstration from Mars in the 2018 time frame. We report on engineering trades for the entire system, and for individual subsystems including the flight terminal, the ground receiver and the ground transmitter. A point design is described to meet the requirement for greater than 0.25 Gb/s downlink from the nearest distance to Mars of 0.42 AU with a maximum mass and power allocation of 40 kg and 110 W. Furthermore, the concept design addresses link closure at the farthest Mars range of 2.7 AU. Maximum uplink data-rate of 0.3 Mb/s and ranging with 30 cm precision are also addressed.
Mars telecom orbiter mission operations concepts
This paper addresses the tall tent pole scenarios and operations conceps that drive the design and operation of MTO.
Performance analysis and comparison of clustered and linearly dispersed optical deep space networks
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Mars Network: A Telecommunications and Navigation Network for Future Mars Exploration
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Mars Network Operations Concept
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Design Considerations for the Mars Network Operations Concept
NASA's Mars Surveyor Program is developing plans for an evolving constellation of satellites in Mars orbit, called the Mars Network, to support the telecommunication and navigation needs of future Mars exploration.
MarsNet: A Mars Orbiting Communications & Navigation Satellite Constellation
Mars has become the focus of an unprecedented series of missions spanning many years, involving numerous nations and evolving from robotic to human exploration.
Mars Network for Enabling Low-Cost Missions
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Technology Infusion in the Era of Faster-Better-Cheaper
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Degradation in finite-harmonic subcarrier demodulation
Previous estimates on the degradations due to a subcarrier loop assume a square-wave subcarrier. This article provides a closed-form expression for the degradations due to the subcarrier loop when a finite number of harmonics are used to demodulate the subcarrier, as in the case of the buffered telemetry demodulator. We compared the degradations using a square wave and using finite harmonics in the subcarrier demodulation and found that, for a low loop signal-to-noise ratio, using finite harmonics leads to a lower degradation. The analysis is under the assumption that the phase noise in the subcarrier (SC) loop has a Tikhonov distribution. This assumption is valid for first-order loops.